On October 1, 1995, at 1415 central daylight time, a Beech A36, N7247W, was substantially damaged during takeoff from a private airstrip near Cotulla, Texas. The private pilot and his 4 passengers were not injured. The airplane, owned by Excellent Aviation Rentals Inc., of Houston, Texas, was being operated under Title 14 CFR Part 91. Visual meteorological conditions prevailed for the business flight for which an IFR flight plan was filed. According to the pilot, the winds were light and variable when he taxied to the northwest end of the 2,200 foot grass airstrip for a departure to the southeast. The pilot added that after completing the run-up and configuring the airplane in a short field takeoff configuration, he applied full power for takeoff. The pilot further stated that initially the airplane accelerated normally until rotation speed was attained for the short field takeoff. The pilot added that after becoming airborne, "the airplane never gained any more airspeed after liftoff, like if something was holding the airplane down." The pilot stated that when he realized that the airplane was not going to be able to clear the trees at the departure end of the airstrip, he elected to abort the takeoff. The airplane came to rest about 200 to 300 feet into the trees. Prior to departing the airstrip, the pilot stated that he had determined that the airplane was within takeoff and CG limits. Additionally, he reported that he calculated the takeoff distance for the prevailing configuration and determined that "they had ample takeoff distance." A review of the performance charts for takeoff distance from the pilot's operating handbook (copies enclosed) revealed the takeoff ground run distance with flaps down and up to be 1,200 and 1,500 feet respectively. Likewise, it was determined that 2,350 and 2,950 feet respectively would be required to clear a 50 foot obstacle with flaps down and up. The height of the obstacles at the departure end of the airstrip was not provided by the either the pilot or the operator.